Which of the following sets of ordered pairs represents a function?

A. {(-6, -5), (-4,-3), (-2, 0), (-2, 2), (0,4)}

B. {(-5, -5), (-5, -4), (-5, -3), (-5, -2), (-5, 0}}

C. {(-4,-5), (-3, 0), (-2,-4), (0, -3), (2, -2}

D. {(-6, -3), (-6, -2), (-5, -3), (-3, -3), (0, 0))